4.9 El Niño and La Niña

Describe the environmental changes and effects that result from El Niño or La Niña events (El Niño–Southern Oscillation).

• El Niño and La Niña are phenomena associated with changing ocean surface temperatures in the Pacific Ocean. These phenomena can cause global changes to rainfall, wind, and ocean circulation patterns.
• El Niño and La Niña are influenced by geological and geographic factors and can affect different locations in different ways.
• Enduring understanding ENG-2: Most of the Earth’s atmospheric processes are driven by input of energy from the sun.